Year	Percent
1991	3.01
1992	2.2
1993	2.06
1994	2.48
1995	3.58
1996	4.25
1997	3.26
1998	4.61
1999	6.35
2000	6.87
2001	6.39
2002	6.27
2003	6
2004	4.9
2005	4.16
2006	3.82
2007	3.27
2008	3
2009	3.58
2010	2.84
2011	2.56
2012	1.97
2013	1.82
2014	1.7
2015	1.81
2016	1.94
2017	1.99
2018	1.83
2019	1.75
2020	2.57